Device and method for discharging a reactive liquid

ABSTRACT

A device and method for dispensing a liquid with a gas includes an instrument having a cannula and a low-pressure tip. The low-pressure tip includes a tip housing that at least partially defines a high pressure chamber. A distal wall of the tip housing includes an aperture in fluid communication with the high pressure chamber. The low-pressure tip also includes a tube and a gas flow channel. The tube fluidly communicates liquid at a relatively low pressure from the cannula through the first aperture. The gas flow channel fluidly communicates gas from the cannula at a relatively high pressure and to the high pressure chamber for discharge from the aperture. The tube and aperture are adapted to dispense the liquid and the gas in order to create a low pressure zone distal of the tube to dispense droplets of the liquid.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of Application Ser. No. 61/681,760filed Aug. 10, 2012, the disclosure of which is hereby incorporated byreference herein.

TECHNICAL FIELD

The present invention relates generally to a low-pressure tip and methodfor dispensing a liquid with a gas from a cannula, and moreparticularly, to a low-pressure tip configured to dispense reactiveliquids and gas for use in a surgical procedure.

BACKGROUND

Generally, it is well-known to dispense liquids in the form of “sprayed”droplets for use in surgical procedures. More specifically, a pluralityof reactive liquids may be sprayed under the influence of pressurizedgas to disperse and dispense the droplets on the human body or withinthe human body to beneficially affect the outcome of the surgicalprocedure. For instance, two highly reactive fluids may be sprayed ontoan anatomical site for reducing the flow of blood by hemostatic clottingor creating tissue barriers to prevent anatomical tissues from adheringtogether during and/or after the surgical procedure. Ideally, thesereactive liquids are isolated prior to being discharged from theinstrument. As such, the reactive liquids mix and react once dischargedfrom the instrument for application at the anatomical site. Thus, thebeneficial characteristics of the reacting fluids are preserved untilneeded for use.

Traditionally, prior to discharging the reactive fluids, the reactivefluids are mixed with high pressure gas within a high pressure chamberof the tip so that the reactive fluids form the sprayed droplets. Manyfluids, such as these reactive fluids, prematurely activate or reactunder the influence of the high pressure. In the event of a prematurereaction between the reactive fluids, the beneficial characteristics aregreatly, if not completely, reduced upon application to the anatomicalsite. Thus, the benefits of the surgical procedure are not fullyrealized in the event of the premature reaction between liquids.

There is a need for an apparatus and method for use in dispensing aliquid with a gas from a cannula, such as during a surgical procedure,that addresses present challenges and characteristics such as thosediscussed above.

SUMMARY

An exemplary embodiment of a device for dispensing a liquid with a gasfor use in a surgical procedure includes an instrument having a cannulaand a low-pressure tip. The low-pressure tip has a tip housing thatincludes a distal wall and at least partially defines a high pressurechamber within the tip housing. The distal wall has a first aperture influid communication with the high pressure chamber. In one aspect, theproximal portion of the tip housing is adapted for attachment to thecannula. More particularly, the proximal portion of the tip housing isattached to the cannula of the instrument.

The low-pressure tip also includes a first tube and a first gas flowchannel. The first tube is adapted to fluidly communicate the liquid ata relatively low pressure from the cannula to distally beyond the highpressure chamber through the first aperture. In addition, the first gasflow channel is adapted to fluidly communicate the gas from the cannulaat a relatively high pressure to the high pressure chamber fordischarging the gas from the first aperture. Accordingly, the first tubeand the first aperture are adapted to dispense the liquid and the gasfor creating a low pressure zone distal of the first tube in order todispense droplets of the liquid.

In another aspect, the low-pressure tip also includes a tip adapter, andat least a portion of the tip housing defines a cavity. The tip adapterincludes the first gas flow channel and the first tube extendingtherethrough. The tip adapter is positioned at least partially withinthe cavity such that the distal wall and the tip adapter further definethe high pressure chamber. As such, the first tube extends through thetip adapter and is configured to insert into the cannula forcommunicating liquid therethrough.

In use, a method for dispensing a first liquid with a gas from alow-pressure tip includes fluidly communicating the gas through thefirst gas flow channel into the high pressure chamber. The method alsoincludes discharging the first liquid from a distal end of the firsttube and discharging the gas from the high pressure chamber through thefirst aperture. In addition, the method includes passing the gas overthe distal end of the first tube and creating a low pressure zone distalof the first tube. The method further includes spraying the first liquidwith the gas and forming droplets from the first liquid.

Furthermore, in one aspect of use, the method includes fluidlycommunicating the gas through the second gas flow channel into the highpressure chamber. The method also includes discharging the second liquidfrom a distal end of the second tube and discharging the gas from thehigh pressure chamber through the second aperture. In addition, themethod includes passing the gas over the distal end of the second tubeand creating a low pressure zone distal of the second tube. The methodfurther includes spraying a second liquid with the gas and formingdroplets from the second liquid.

In another aspect, the method of forming droplets also includes mixingthe first and second liquids to create droplets having both first andsecond liquids.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention and,together with a general description of the invention given above, andthe detailed description given below serve to explain the invention.

FIG. 1 is a perspective drawing of one embodiment of an instrumenthaving a low-pressure tip.

FIG. 1A is a perspective drawing of the low-pressure tip of FIG. 1attached to a cannula of the instrument.

FIG. 2 is a perspective drawing of the low-pressure tip of FIG. 1 havingthe tip housing shown by hidden lines.

FIG. 3 is a cross-sectional side view of the low-pressure tip of FIG. 1.

FIG. 4 is a front view of the low-pressure tip of FIG. 1.

DETAILED DESCRIPTION

With reference to FIGS. 1-1A, an exemplary embodiment of thelow-pressure tip 10 for dispensing a reactive liquid with a gas,particularly with respect to instruments used in surgical procedures, isattached to an instrument 12 having a cannula 14. While the low-pressuretip 10 may be used with any appropriate gas assisted liquid dispensinginstrument or device, examples of such devices include applicators soldunder the FibriJet® name by Nordson Micromedics, of St. Paul, Minn. Thecannula 14 may be rigid, flexible, or flexible and steerable. Theapplicator 12 may be manual, such as those that utilize one or moremanually actuated syringes, or may be powered in any desirable manner.In any case, the cannula 14 is adapted to be in fluid communication withthe low-pressure tip 10 for delivering a pressurized fluid to thelow-pressure tip 10. Generally, the applicator 12 may be any medicalinstrument used for dispensing reactive liquids with a gas, such thatthe reactive liquids dispense as droplets for application on a desirablesurface. More particularly, the cannula 14 of the applicator 12 isadapted to deliver a plurality of reactive liquids and a gas to thelow-pressure tip 10 for dispensing droplets from the low-pressure tip 10onto an anatomical site during medical procedures. Such medicalprocedures for use with the low-pressure tip 10 may include topicalapplications, open surgical applications, and minimally invasiveapplications such as laparoscopy.

The exemplary embodiment of the low-pressure tip 10 is generallycylindrically shaped and includes a tip housing 16, a hypodermic tube18, and a gas aperture 20. The tube 18 and the aperture 20 are each influid communication with the applicator 12. Generally, the low-pressuretip 10 is adapted to be connected to the cannula 14 at a proximal endportion 22 of the tip 10. In addition, the tube 18 and the aperture 20are in fluid communication with the cannula 14 and are adapted todispense the liquid from the tube 18 and the gas from the aperture 20 ata distal end portion 24 of the tip 10. More particularly, the exemplaryembodiment of the invention includes a pair of tubes 18, 25 fordispensing first and second reactive fluids, such as first and secondreactive liquids, and a pair of apertures 20, 26 for dispensing asingle, generally inert gas around the first and second reactiveliquids, such as CO₂ or air. It will be appreciated, however, that anynumber of tubes and apertures may be respectively used with any numberof reactive liquids and gases, and the invention is not intended to belimited to the exemplary embodiment.

With respect to the tip housing 16, the proximal end portion 22 isadapted to be connected to the cannula 14. The proximal end portion 22is also tapered to reduce the lip between the tip housing 16 and thecannula 14 for improving performance of the low-pressure tip 10 duringuse. For instance, tapering the proximal end portion 22 reduces thelikelihood that the low-pressure tip 10 will catch on an externalcommunicating device, such as a trocar, while being removed. The cannula14 is inserted into the low-pressure tip 10 in order to place theapplicator 12 in fluid communication with the pair of tubes 18 andapertures 20. Each of the first and second liquids and the gas areisolated from each other within the low-pressure tip 10. Accordingly,the distal end portion 24 of the tip housing 16 includes a wall 27through which the apertures 20 extend, that separates the gas from thereactive liquids. However, as the gas is fluidly communicated distal ofthe wall 27 and the liquid is fluidly communicated distal of the tube20, the fluids mix to form liquid droplets.

As shown in FIGS. 2-3, the tip housing 16 defines an interior cavity 28therein. According to the exemplary embodiment, the interior cavity 28has a distal cavity portion 30 and a proximal cavity portion 32. Theproximal cavity portion 32 has an opening 34 at the proximal end portion22 and is sized and adapted such that the cannula 14 is sealablyinserted therein. Moreover, a tip adapter 36 is inserted into at least aportion of the interior cavity 28 between the distal cavity portion 30and the cannula 14. Accordingly, the tip adapter 36, the wall 27, andthe distal cavity portion 30 define a high pressure chamber 38 in fluidcommunication with both the apertures 20 and a pair of gas lumens 40, 41(see FIGS. 2 and 4) within the cannula 14 adapted to deliver thepressurized gas (as indicated by arrows 42).

The tip adapter 36 receives the tubes 18, 25 as each extends through thetip adapter 36 and reaches proximal from the tip adapter 36 forinsertion into the reactive fluid lumen (not shown) within the cannula14. Thereby, the tubes 18, 25 are fluidly connected with the reactiveliquids from the cannula 14. The tubes 18 also extend distally from thetip adapter 36 through the high pressure chamber 38 and through at leasta portion of the apertures 20. As shown in the exemplary embodiment,each of the tubes 18, 25 terminates distal of the wall 27 fordischarging reactive liquid (as indicated by arrows 44).

Moreover, the tip adapter 36 includes a gas flow channel 46 in fluidcommunication with the gas lumen 40 and the high pressure chamber 38 fortransporting high pressure gas from the gas lumen 40 to the pressurizedchamber 38. According to the exemplary embodiment, the tip adapter 16includes a pair of gas flow channels 46, 47; however, it will beappreciated that any number of gas flow channels 46, 47 may be so used.While the gas flow channels 46, 47 are isolated from each other, theirfluid communication into the high pressure chamber 38 is commonly sharedsuch that the high pressure gas from each of the gas flow channels 46,47 enters the high pressure chamber 38 for discharge through theapertures 20, 26. For example, the pressure of the gas 42 within thehigh pressure chamber 38 is approximately 5 psi. However, the inputpressure at the proximal end will typically be higher to account forpressure drop between the proximal and distal ends of the applicator 12and/or low-pressure tip 10. Such pressure of the pressurized gas 42 hasbeen shown to work well for applications in which the reactive liquids44 comprise blood and thrombin for causing hemostatic clotting at ananatomical site.

The high pressure, pressurized gas 42 discharges through a pair ofcircumferential flow gaps 48, 49 defined by the circumferential spacebetween each of the tubes 18, 25 and the respective apertures 20, 26. Assuch, the high pressure gas discharges from the pair of circumferentialflow gaps 48, 49 surrounding the tubes 18, 25 distal of the wall 27.

FIG. 4 shows the generally central and vertically symmetrical placementof the apertures 20, 26 and the tubes 18, 25 extending therethrough fromthe wall 27 to the cannula 14. The wall 27 is shown as being generallyflat. However, the wall 27 may also be modified in a variety ofconfigurations for producing any one of a variety of spray patterns orconfigurations. Moreover, the gas lumens 40 are shown relatively centraland horizontally symmetrical through the cannula 14. In addition, thewall 27 may include a plurality of nodes 50 extending at least partiallyinto the pair of flow gaps 48, 49. The plurality of nodes 50 aregenerally symmetrically positioned surrounding the pair of tubes 18, 25and configured to maintain the flow gaps 48, 49 surrounding the tubes18, 25. Accordingly, the plurality of nodes 50 prevents each of thetubes 18, 25 from traveling either vertically or horizontally within therespective apertures 20, 26 in order to maintain the circumferentialplacement of each flow gap 48, 49. Thereby, the pressurized gasdischarges generally circumferentially and uniformly around the tubes18, 25. It will be appreciated, however, that vertical and horizontaldirections are intended to be relative to the exemplary embodiment inFIG. 4, and that such directions are not intended to limit theinvention. Generally, the cannula 14 includes the pair of gas lumens 40,41 and a pair of reactive liquid lumens (not shown) in fluidcommunication with the tubes 18, 25 as described herein. However, afifth lumen (not shown) may be provided for the steerable/flexiblecannula for holding a steerable guide wire so that a doctor, or similarpractitioner, may more accurately and easily direct the low-pressure tip10 to a desired target.

In order to use the low-pressure tip 10 with the applicator 12, thelow-pressure tip 10 is inserted onto the cannula 14 of the applicator 12so that the tubes 18, 25 align with the reactive liquid lumens (notshown) and the gas flow channels 46, 47 align with the gas lumens 40,41. The tubes 18, 25 are in fluid communication with the reactive liquidlumens and dispense the reactive fluids, at relatively low pressure,distal of the tubes 18, 25. The gas flow channels 46, 47 are in fluidcommunication with the gas lumens 40, 41 such that the gas, atrelatively high pressure, travels through the gas flow channels 46, 47and enters the high pressure chamber 38.

The high pressure chamber 38 forces the gas circumferentially throughthe flow gaps 48, 49 surrounding the tubes 18, 25 at a relatively highpressure. Generally, the velocity of the gas is greater than thevelocity of the reactive liquids; however, the gas discharges throughthe apertures 20, 26 having laminar flow. As the laminar flow of the gaspasses distally over the tubes 18, 25, a low pressure zone is created ateach of the discharging reactive liquids. The low pressure zone furtheraccelerates each of the reactive liquids causing the reactive liquids todischarge or “spray” from the low-pressure tip with the gas. This sprayof the reactive liquids creates droplets of the reactive liquids forapplication during medical procedures, such as surgery. Thereby, thereactive liquids are not mixed or formed into droplets while at therelatively high pressure in order to prevent the reactive liquids fromprematurely reacting at the high pressure for proper application.

While the present invention has been illustrated by the description ofone or more embodiments thereof, and while the embodiments have beendescribed in considerable detail, they are not intended to restrict orin any way limit the scope of the appended claims to such detail.Additional advantages and modifications will readily appear to thoseskilled in the art. The invention in its broader aspects is thereforenot limited to the specific details, representative apparatus and methodand illustrative examples shown and described. Accordingly, departuresmay be from such details without departing from the scope or spirit ofthe general inventive concept.

What is claimed is:
 1. A device for dispensing first and second liquids with a gas for use in a surgical procedure, comprising; an instrument having a cannula; and a low-pressure tip, comprising; a tip housing having a distal wall and a proximal portion, the tip housing at least partially defining a high pressure chamber therein and the distal wall having a first aperture in fluid communication with the high pressure chamber, the proximal portion being attached to the cannula; a first tube adapted to fluidly communicate the first liquid at a first pressure from the cannula to distally beyond the high pressure chamber through the first aperture; and a first gas flow channel adapted to fluidly communicate the gas from the cannula at a second pressure to the high pressure chamber for discharge from the first aperture, the second pressure being higher than the first pressure, wherein the first tube and the first aperture are adapted to dispense the first liquid and the gas for creating a low pressure zone distal of the first tube in order to dispense droplets of the first liquid, wherein the distal wall has a second aperture in fluid communication with high pressure chamber, and the low-pressure tip further comprises: a second tube adapted to fluidly communicate the second liquid at the first pressure from the cannula to distally beyond the high pressure chamber through the second aperture; and a second gas flow channel adapted to fluidly communicate the gas from the cannula at the second pressure to the high pressure chamber for discharge from the second aperture, the first and second gas flow channels having separate channel apertures at the high pressure chamber, wherein the second tube and the second aperture are adapted to dispense the second liquid and the gas for creating the low pressure zone distal of the second tube in order to dispense droplets of the second liquid, wherein the first and second tubes extend through the respective first and second apertures and past the distal wall, wherein the first and second tubes and the first and second apertures define respective first and second gas flow gaps, the first and second gas flow gaps being in fluid communication with the high pressure chamber for dispensing the gas therethrough.
 2. The device of claim 1 wherein at least a portion of the tip housing defines a cavity, the device further comprising: a tip adapter having the first and second gas flow channels and the first and second tubes extending therethrough, the tip adapter positioned at least partially within the cavity such that the distal wall and the tip adapter further define the high pressure chamber within the tip housing, wherein the first and second tubes extending through the tip adapter insert into the cannula for communicating the first and second liquids therethrough.
 3. The device of claim 1, wherein the first flow gap surrounds the first tube for discharging gas generally circumferentially around the first tube and the second flow gap surrounds the second tube for discharging gas generally circumferentially around the second tube.
 4. The device of claim 3 wherein the distal wall includes a plurality of nodes extending at least partially into the first and second flow gaps for preventing the first and second tubes from moving respectively within the first and second apertures and maintaining the circumferential first and second flow gaps.
 5. A low-pressure tip for dispensing first and second liquids with a gas from a cannula for use in a surgical procedure, comprising; a tip housing having a distal wall and a proximal portion, the tip housing defining a high pressure chamber therein and the distal wall having a first aperture in fluid communication with the high pressure chamber, the proximal portion adapted for attachment to the cannula; a first tube adapted to fluidly communicate the first liquid at a first pressure from the cannula to distally beyond the high pressure chamber through the first aperture; and a first gas flow channel adapted to fluidly communicate the gas from the cannula at a second pressure to the high pressure chamber for discharge from the first aperture, the pressure being higher than the first pressure, wherein the first tube and the first aperture are adapted to dispense the first liquid and the gas for creating a low pressure zone distal of the first tube in order to dispense droplets of the first liquid, wherein the distal wall has a second aperture in fluid communication with high pressure chamber, and the low-pressure tip further comprises: a second tube adapted to fluidly communicate the second liquid at the first pressure from the cannula to distally beyond the high pressure chamber through the second aperture; and a second gas flow channel adapted to fluidly communicate the gas from the cannula at the second pressure to the high pressure chamber for discharge from the second aperture, the first and second gas flow channels having separate channel apertures at the high pressure chamber, wherein the second tube and the second aperture are adapted to dispense the second liquid and the gas for creating the low pressure zone distal of the second tube in order to dispense droplets of the second liquid, and wherein the first and second tubes extend through the respective first and second apertures and past the distal wall, and wherein the first and second tubes and the first and second apertures define respective first and second gas flow gaps, the first and second gas flow gaps being in fluid communication with the high pressure chamber for dispensing the gas therethrough.
 6. The low-pressure tip of claim 5 wherein at least a portion of the tip housing defines a cavity, the device further comprising: a tip adapter having the first and second gas flow channels and the first and second tubes extending therethrough, the tip adapter positioned at least partially within the cavity such that the distal wall and the tip adapter further define the high pressure chamber within the tip housing, wherein the first and second tubes extending through the tip adapter is configured to insert into the cannula for communicating the first and second liquids therethrough.
 7. The low-pressure tip of claim 5 wherein the first flow gap surrounds the first tube for discharging gas generally circumferentially around the first tube and the second flow gap surrounds the second tube for discharging gas generally circumferentially around the second tube.
 8. The low-pressure tip of claim 7 wherein the distal wall includes a plurality of nodes extending at least partially into the first and second flow gaps for preventing the first and second tubes from moving respectively within the first and second apertures and maintaining the circumferential first and second flow gaps. 